Specification

High Performance Zero-Leakage Bellow Seal Globe Valve Connection Size available from DN15 to DN350

PN 16
DN	Main connection size
DN	L	D	D1	D2	b	f	H	n-Φd
15	130	95	65	45	16	2	197	4-Φ14
20	150	105	75	58	18	2	197	4-Φ14
25	160	115	85	68	18	2	205	4-Φ14
32	180	140	100	78	18	2	208	4-Φ18
40	200	150	110	88	18	3	230	4-Φ18
50	230	165	125	102	20	3	233	4-Φ18
65	290	185	145	122	22	3	254	4-Φ18
80	310	200	160	138	24	3	277	8-Φ18
100	350	235	180	158	24	3	365	8-Φ18
125	400	250	210	188	26	3	392	8-Φ18
150	480	285	240	212	28	3	420	8-Φ22
200	600	340	295	268	34	3	580	12-Φ22
250	650	405	355	320	33	3	750	12-Φ25
300	750	460	410	375	33	4	925	12-Φ25
350	850	520	470	435	34	4	1030	16-Φ25
PN 25
15	130	95	65	45	16	2	197	4-Φ14
20	150	105	75	58	18	2	197	4-Φ14
25	160	115	85	68	18	2	205	4-Φ14
32	180	140	100	78	18	2	208	4-Φ18
40	200	150	110	88	18	3	230	4-Φ18
50	230	165	125	102	20	3	233	4-Φ18
65	290	185	145	122	22	3	254	8-Φ18
80	310	200	160	138	24	3	277	8-Φ18
100	350	235	190	162	24	3	355	8-Φ22
125	400	270	220	188	26	3	410	8-Φ26
150	480	285	240	212	28	3	420	8-Φ26
200	600	340	310	278	30	3	540	12-Φ26
250	650	405	355	335	32	3	750	12-Φ30
300	750	460	410	375	34	4	925	16-Φ30
350	850	520	470	435	34	4	1030	16-Φ33
PN 40
15	130	95	65	45	16	2	195	4-Φ14
20	150	105	75	58	18	2	195	4-Φ14
25	160	115	85	68	18	2	207	4-Φ14
32	160	140	100	68	18	2	218	4-Φ18
40	180	150	110	78	18	3	225	4-Φ18
50	230	165	125	102	20	3	230	4-Φ18
65	290	185	145	122	22	3	272	8-Φ18
80	310	200	160	138	24	3	290	8-Φ18
100	350	235	190	162	24	3	355	8-Φ22
125	400	270	220	188	26	3	410	8-Φ26
150	480	300	250	218	28	3	425	8-Φ26
200	600	340	310	278	34	3	540	12-Φ30

Product Overview

DN15~DN350 PN16~PN40 High Performance Zero-Leakage Bellow Seal Globe Valve for Hot Oil

I. Product Overview

TIANYU high performance zero-leakage bellow seal globe valve is a specialized flow control solution engineered for hot oil systems and high-temperature industrial pipelines. Crafted with carbon steel (GS-C25) and stainless steel (SS304, SS321, 1.4401), it features a bellow seal structure and flanged connection to ensure precise on-off and throttling control of hot oil, as well as other high-temperature media like steam and industrial fluids. Operating at -20℃~425℃ and PN16~PN40 pressure, it leverages a stainless steel bellow (SS321/SS316) to replace traditional packing seals, eliminating stem leakage—a critical issue in conventional valves handling hot oil. Compliant with DIN, GB, ANSI, and JIS standards, it is ideal for petroleum refining, chemical processing, industrial heating, and energy industries where zero leakage and high-temperature stability are essential.

II. Key Attribute Parameters

Size Range: DN15~DN350, covering small to medium-diameter pipelines for hot oil transfer and control.
Pressure Range: PN16~PN40 (1.6MPa~4.0MPa), adapting to medium-pressure systems such as hot oil circulation loops and industrial heating pipelines.
Temperature Range: -20℃~425℃, with SS321 bellow and 1.4401 body retaining stability in high-temperature cycling—critical for hot oil (typically 200℃~350℃).
Material Configuration:
- Body & Bonnet: GS-C25 (cost-effective for general hot oil), SS304/1.4401 (corrosion resistance), SS321 (high-temperature oxidation resistance).
- Bellow: SS321 (primary, withstands 425℃) or SS316 (corrosive hot media), ensuring flexibility under thermal expansion.
- Disc & Seat: 2Cr13, Stellite (Stl) for wear resistance; metal-to-metal sealing adapts to high-temperature hot oil without soft seal degradation.
- Stem: 1.4401/2Cr13, connected to bellow to isolate from hot oil and prevent leakage.
- End Connections: Flanged (per DIN/ANSI standards), ensuring leak-tight integration with hot oil pipelines.
Actuation: Manual (handwheel), with smooth operation even under high-temperature conditions.
Design & Test Standards: Design follows DIN/GB/ANSI; testing includes hydrostatic strength (1.4×PN) and sealing (1.0×PN) per industry standards.

III. Features Description

Dual Sealing Zero Leakage: Combines bellow seal (primary) and packing seal (secondary) to eliminate stem leakage. The SS321 bellow forms a hermetic barrier, avoiding hot oil seepage that could cause energy loss or safety hazards—unlike traditional packing seals that harden and leak under high temperature.
Scraping Disc Design: The disc features a unique scraping edge that cleans the seat surface during operation, removing coked oil residues (common in hot oil systems) and reducing wear. This extends seal life by 50% compared to standard discs.
High-Temperature Bellow Stability: SS321 bellow resists creep and oxidation at 425℃, maintaining flexibility through 10,000+ thermal cycles (hot oil heating/cooling). It compensates for stem expansion, avoiding seal failure from temperature-induced deformation.
Lightweight & Easy Operation: Optimized body structure reduces weight by 15% vs. conventional globe valves, making manual operation easier—critical for large-diameter valves in hot oil plants where frequent adjustment is needed.
Wide Standard Compatibility: Complies with DIN, GB, ANSI, and JIS, fitting seamlessly into global hot oil systems. Flange dimensions match pipeline standards, avoiding adaptation issues in cross-border projects.

Valve Details

IV. Manufacturing Processes

Material Validation: SS321/1.4401 materials undergo spectral analysis to verify alloy content (e.g., SS321 contains Ti to resist intergranular corrosion). Bellows are tested for fatigue resistance via 10,000 thermal cycles at 425℃.
Bellow Forming: SS321 sheets are rolled into tubes, then hydraulically formed into corrugated bellows. TIG welding connects the bellow to stem and bonnet, with helium leak testing (≤1×10⁻⁹ Pa·m³/s) to ensure hermetic sealing.
Precision Machining: Disc and seat are CNC-ground to Ra ≤1.6μm, ensuring tight contact. The disc’s scraping edge is honed to 0.8μm roughness to avoid damaging the seat while cleaning residues.
Assembly & Testing:
- Hydrostatic Test: Body tested at 1.4×PN (e.g., 5.6MPa for PN40) for 30 minutes; seat tested at 1.0×PN with hot oil (300℃) to simulate real working conditions.
- High-Temperature Operation Test: Valve is heated to 425℃, operated 100+ cycles to verify bellow flexibility and sealing integrity.
- Gas Seal Test: 0.5MPa air test confirms no leakage at stem and flange connections.

V. Product Advantages

Zero Leakage for Hot Oil: Dual sealing eliminates hot oil loss, reducing energy waste by 20% in circulation systems and avoiding fire risks from leaked flammable hot oil.
Resistance to Coking & Wear: Scraping disc prevents coked oil buildup on seats, maintaining sealing performance and reducing maintenance frequency in heavy oil applications.
Long Service Life in High Temperature: SS321 bellow and wear-resistant disc/seat extend service life to 8~10 years—twice that of standard globe valves in hot oil environments.
Easy Maintenance: Lightweight design and modular structure simplify disassembly; bellow and seat can be replaced without removing the valve from the pipeline, cutting downtime by 40%.
Safety & Compliance: Zero leakage and high-temperature stability meet safety standards for flammable hot oil systems, reducing accident risks in refineries and chemical plants.

Application

VI. Application Fields

Petroleum Refining: Controls hot oil flow in distillation units and asphalt processing, where high temperature (250℃~350℃) and oil coking are common—scraping disc avoids seat blockage.
Industrial Heating: Regulates thermal oil flow in district heating or factory heating loops, with zero leakage ensuring efficient heat transfer and no energy loss.
Chemical Processing: Manages hot oil used as heat carrier in reaction kettles, with SS316 bellow option resisting corrosion from oil containing chemical additives.
Food & Pharmaceutical: Controls food-grade hot oil (e.g., in edible oil refining), with SS304 material avoiding contamination and meeting hygiene standards.
Energy Sector: Regulates hot oil in solar thermal or biomass energy systems, adapting to temperature fluctuations (100℃~300℃) without seal failure.